Device for locking platens of typewriters



Oct. 9, 1945. J. P. C AMZI DEVICE FOR LOCKING THE PLATEN OF A TYPEWRiTER Filed Dec. 6, 1943 1 Camzz:

Patented Oct. 9, 1945 DEVICE FonLooKING PLATENS. or

TYPEWRITERS Jules Paul 'Camzi, Geneva, Switzerland Application December 6, 1943, Serial No. 513,104

In Switzerland March 1943 7C1aims. (Cl. *19 7 141) This invention relates to accessories for type- 1 writers in the form of regulating devices for the platen roller feed whereby rotation of the platen and feed of the paper can be arrested at any predetermined line of writing and the operator can ascertain at a glance the number of lines written on a sheet and the number of lines remaini-ng;

The primary object of the invention is to provide asimple and reliable device of this kind.

The device according to the invention comprises an internally toothed crown coaxial with the platen rollerand having a series of notches around its periphery, a pinion in Constant engagement with the teeth of said crown, said pinion being rotatable by said platen roller to turn said crown at slow speed relatively to said roller, a stop member rota-ting with said crown, said stop member being settable coaxially with said crown to engage any of the notches therein, and a fixed stop in the path of said rotating stop member and arranged to block further movement thereof and of the platen roller when said platen roller has turned through a predetermined angle of paper feed] The accompanying drawing, which is given solely as an example, shows several embodiments shaft I of the usual platen roller 2 the rotation .of which feeds the paper sheet, not shown, extends through three discs 3, .4 and 5. and can turn relatively thereto-whereasa pinion B is fixed to this shaft I and is constantly in mesh with a pinion 1 which can rotate about a shaft '8i1xed to the disc 3, which latter is itself fixed ,to the usual carriage 9 whereby said disc 3 is unable to revolve. The pinion Us in mesh withan internal toothed crown ID on the disc 4. said di c has external slots II into each of which can penetrate a part [2 of a stop I,3 .fast on the disc 5 which latter is pushed by a spring l-sl located .be-

tween this disc and the usual roller turning knurled knob Hi. The stop I 3;is adapted tothrust against another stop l5 fixed on the disc The pinions 6, I produce rotation .of the disc i in the reverse direction to that of .the roller and change the speed ratio so that the disc 4 rev s l ss than one tu n f r tha hi lh er .Q revolu i ns 0f the platen ,rqller 2 corresponding to t upwa d m v nt to h perform d by th longest pa er she t on whic the y in i to b besi s leav n -the regu r w ot ma in on tl1e..$heet. a 1

I o d to set the ma imum o ibl r tation an le of the disc A and cons qu ntl to {d te mine the numbe of turns 1? hetc l nsler it is ne ssaryonly to introduce the stop L3 into the proper lot 11;, the passaee z hom. n Slot to h n x being .obtained easi ygdue-to the a t that the disc ,5 can separate axially from the disc .4 by compressing the spring M. The operator working on the ma ne can o ser e h m emen .o t e s p 13 app o ch ng n arer and n a t the stop I5 and, when the pitch of the slots corranonds to a le in e line s ace; i w ll be e y to judge the space still ayailablfi; the disc .4 is also prpyided with-graduations, not represented, howin th umbe of ine wh c a t ll =totyped and whichtdep nds n t e gu a distan e r maini g be ween th two s e s- In the embodiment shown 1i r 1;;1 igs.,5 to 14 the stop device includes a sleeve I?!- and set screws 428. 'w e eh t -d vi e ma b fix d nih ha of the pla o e e t e ma h in rch ngeable sleeves such as t9, oor-respend {to different vdiarneters of stheaxles ,such as 20 "Th i e i e udes ta -disc 2. with pen n s '22 therein Fig 118). As on-pi wi ha-h ck 23a-withparal1el flats therein can be fixed in any on p the op n n s a Ye -0 n ne-; A in :a c p sha ed d .25 which i n ri ed with a pin 25 penetrating into one of a series pf :holes 2,?! iipthedisc 24. Thus-one determines :andset s, when a emhl ns theid i e, th relat v osi ons 10 th cup shap di c and of th d sc 2 a-t;te hears .g-radaat ons land tast a le t rr a e of th mach n b .a.1: ug plat :28 Pr d d w th a sl en wh ch :the stop 5& en tra s h s pla 28 be t e traversed at an. by fixin :SFJIKQWS th a d into th usua ca ia e. 32 15a m va uidi g inde i o de to allow a quick setting of a part 33-,of a movable stop 33 in front.of that.one ;of.a,seri e sof,. slots .34 which c r es o ds .tothestartin -n t on fo a determined paper sheet size. .Grooves 3,5, 36 .31

'a p oridsdno n ing with a1 al 8 pressed y s ng toret a d c-4. beatin t em a-ble stop ,33, in the following positions: ,(a) -Position shown on theldrawing wherein theslots 34 and index32 are released with regard to an elastic stop '4]. ('22) "Release with regard tothe stop H and the slots 34, but in such a way that a thrust is developed against the index 32. Position of engagement in the slots 34 and thrust against stop 4|. This provision avoids the difficulty which might arise in reading the graduations which are at the back of the machine. The groove 35 is of less depth than the two others in order that, when passing from 35 to 36, the necessary strain should be very small and also to overcome the risk of overrunning the groove 36.

The index 32 is easily adjustable by hand by operating on the part 32 located above a slide.- It can not be displaced by the movable stop 33- which operates only on the extremity of said index, this latter then having a tendency to tilt within the slide. Figs. 13 and 14 clearly show the arrangement of this index 32 with. inserticn'of compressible packing 32*.

On the sleeve I1 is keyed a pinion 42 meshing with a pinion 43 meshing in turn with a pinion 44 in mesh with the toothed crown 45, the arrangement being such that the rotation of said crown is in the same direction as that of the platen roller of the machine.

The stop 4| is mounted on a lever 46 with opposing spring 41 and oscillates about an axle 48 fastened to the disc 2|, the oscillating movement being limited by a slot 49 in the disc 2|. This lever 46 drives an elastic arm 50 of a hammer the striking of which against the cup shaped disc 25 produces a signal-sound; Fig. 12- shows that the arm 50 in its resting position is located within a groove of a piece 52 so that a convenient release can take place for the striking of the hammer. In an electrically driven typewriter the movement of the lever 46 can actuate a switch to cut off the electric current and stop the machine.

The graduation can be marked on a removable strip in order to change the graduation corresponding to different platen roller diameters, and multiple graduations can be marked for difierent line spacings. Two graduations can be provided reading in opposite directions whereby the device may be placed either at the right hand or at the left hand of the machine.

The slots are chamfered at one side of their edges as shown in Fig. 5 when the device is to be placed at the right hand of the machine, and they are chamfered on the opposite side when the device is to be placed at the left hand side. In this case it is suflicient to change the disc provided with these grooves. The chamfering on only one side is for the purpose of avoiding the clamping of part 33 between the'index 32 and the wall of the slot.

The fixation of the disc 2| can be obtained by simply inserting the stop 23 within an opening made in the carriage; however the use of the plate 28, in most of the cases, avoids a manufacturing operation, since the holes 30 and 3| correspond to tapped holes already existing in the usual carriages to receive screws for securing components of the machine; the plate 28 is then inserted between the heads of these screws and the carriage.

In the embodiment shownin Figs. 15 and 16 instead of concentric toothed wheels, bevel gears are used. A plate 53 is fastened to the carriage, a second plate 54 bearing a toothed wheel revolves concentrically with respect to the first one, and is driven by;a bevel gear 55 fast on the axle of the machine. The planes of these plates are parallel to this axle, the movable stop 56 is introduced into one of the grooves 51 of the plate 54, the fixed stop being located in 58, This embodiment is provided with only two grooves 59, 60 instead or the three grooves 35, 36, 31, due to the fact that the need to facilitate the setting at the starting position is not necessary, because the graduation is quite visible.

What I claim as my invention and desire to secure by Letters Patent of the United States is:

1. A platen roller feed regulating device for typewriters comprising an internally toothed crown coaxial with the platen roller, said crown having a series of notches around its periphery, an intermediary pinion in constant engagement with the teeth of said crown, said pinion being rotatable by said platen roller to turn said crown at slow speed relatively to said roller, a stop member rotating with said crown, said stop member being settable coaxially with said crown to engage any of the notches therein, and a fixed stop in the path of said rotating stop member and arranged to block further movement thereof and of the platen roller when said platen roller has turned through a predetermined angle of paper feed.

2. A platen roller feed regulating device for typewriters comprising, a toothed crown disposed with its axis transverse to the axis of the platen roller and having a series of notches concentric with the crown teeth, a bevel pinion in permanent gear with said crown teeth, said pinion being rotatable by said platen roller to turn said crown at slow speed relatively to said roller, a stop member rotating with said crown, said stop member being settable coaxially with said crown to engage any of the notches therein, and a fixed stop in the path of said rotating stop member and arranged to block further movement thereof and of the platen roller when said platen roller has turned through a predetermined angle of paper feed. I

3. A platen roller feed regulating device for typewriters comprising an internally toothed crown coaxial with the platen roller, said crown having a series of notches chamfered on one edge around its periphery, an intermediary pinion in constant engagement with the teeth of said crown; said pinion being rotatable by said platen roller to turn said crown at'slow speed relatively to said roller, a stop member rotating with said crown, said stop member being settable coaxially with said crown to engage any of the notches therein, and a fixed stop in the path of said rotating stop member and arranged to block further movement thereof and of the platen roller when said platen roller has turned through a predetermined angle of paper feed.

4. A device according to claim 1 wherein the platen roller has a shaft to which the toothed crown is concentric and is permanently in mesh with said intermediary pinion which is itself constantly in mesh with another pinion fast on said shaft.

5. A device according to claim 1 wherein the platen roller has a shaft to which the toothed crown is concentric and is permanently in mesh with said intermediary pinion which is itself constantly in mesh with another pinion fast on said shaft, said device also comprising three discs loose on said roller shaft, the first of these discs being fixed to the typewriter and carrying said intermediary pinion, said second disc carrying the internally toothed crown with said series of notches provided externally thereon, and said third disc carrying'said settable stop member.

6. A device according to claim 1 wherein said fixed stop comprises a spring permitting slight oscillation, and comprising a sound-signal lever actuated by said oscillation when said fixed stop is encountered by the settable stop member.

7. A device according to claim 1, comprising an index of the writing line position, a support for the settable stop, and spring and ball retaining means for holding said support in three positions, the first one in which said settable stop is released with regard to the fixed stop, the notches and said index, the second in which said settable stop is released with regard to the fixed stop and the notches but exerts thrust on said index, and the third position in which said settable stop is engaged in the notches and follows a path wherein it will encounter said fixed stop.

' JULES PAUL CAMZI. 

